Biology subjects

Mignotte, A.

Publications and source records attributed to Mignotte, A..

3 recordsLinked to original sources

bioRxiv2026

Early-warning surveillance of West Nile and Usutu viruses in water and mosquito excreta using digital PCR

1.West Nile virus (WNV) and Usutu virus (USUV) are mosquito-borne pathogens maintained in bird-mosquito cycles and increasingly cause human and equine disease in temperate regions. As most infections are asymptomatic, surveillance based on clinical and veterinary reports provides delayed signals for vector control and equine vaccination strategies. We implemented, in 2024 and 2025, an operational environmental surveillance strategy combining molecular xenomonitoring of adult mosquito excreta with water sampling from wetlands and mosquito breeding sites, coupled to a standardized multiplex reverse transcription digital PCR workflow. Viral detection was performed using a multiplex digital PCR assay with characterized limits of blank, detection, and quantification, and low-level positives were confirmed by Sanger sequencing. This multi-matrix approach detected WNV RNA in southern France as early as 1 July 2024, 40 days before the first human case and 67 days before the first equine alert, and on 9 April 2025, a full 19 weeks ahead of the first human case that year. USUV RNA was similarly detected from 5 July 2024 and 22 April 2025, providing actionable early warnings to guide targeted vector control and preparedness. Across both years, WNV and USUV were detected 29 and 8 times among 396 samples in 2024, and 90 and 14 times among 815 samples in 2025, revealing previously unrecognized, cryptic virus circulation. These results demonstrate that integrating environmental surveillance provides a sensitive, proactive framework for the early detection of emerging Culex-borne arboviruses, offering precious lead time for public one-health strategies.

ecology↗

bioRxiv2025

Temperature is the key weather determinant of Aedes albopictus seasonal activity in southern France

The presence and the activity of Aedes albopictus are a growing concern for nuisance and public health in Europe. Vector control operators, public health officers, and communities look for weather-based decision support systems to inform mosquito management policies. Despite an increasing number of entomological and modelling studies, our incomplete understanding of mosquito population response to weather drivers in natural conditions restricts the development of sound vector management policies. Here, we aim to clarify the role of weather conditions on Ae. albopictus presence and abundance in four sites in southwestern France. We rely on ovitrap longitudinal records collected on a 1-2 weeks basis and weather time series over 2023 and 2024 to model oviposition activity. Our analysis combines a mechanistic model from literature and a new machine learning model fitted on cross-correlated lagged weather predictors. Both models satisfactorily reproduce the observed oviposition dynamics, correctly predicting the onset and the end of the activity - periods that existing models have often inadequately captured. Temperature plays a major role in triggering the presence of Ae. albopictus, explaining the interannual variation of oviposition in all sites, especially in spring and autumn. In fact, warm springs and autumns extend the periods in which Ae. albopictus life-history traits (fertility, development, survival) approach their thermal optima. In summer, a more prominent role of rain and humidity emerges among secondary drivers of oviposition intensity. This work contributes to the development of operational weather-driven forecasting tools for Ae. albopictus activity to support vector control operations in different biogeographical contexts.

ecology↗

bioRxiv2023

Multiplexed amplicon sequencing reveals the heterogeneous spatial distribution of pyrethroid resistance mutations in Aedes albopictus mosquito populations in Southern France.

The risk of mosquito-borne diseases transmission is moving fast toward temperate climates with the colonization and proliferation of the Asian tiger mosquito vector Aedes albopictus and the rapid and mass transport of passengers returning from tropical regions where the viruses are endemic. The prevention of major Aedes-borne viruses heavily relies on the use of insecticides for vector control, mainly pyrethroids In Europe. High-throughput molecular assays can provide a cost-effective surrogate to phenotypic insecticide resistance assays when mutations have been previously linked to a resistance phenotype. Here, we screened for the spatial distribution of kdr mutations at a large scale using a two-step approach based on multiplexed amplicon sequencing and an unprecedented collection of field-derived mosquitoes in South of France. We identified the presence of the V1016G allele in 14 sites. The V1016G allele was predominantly found in South-East France close to the Italian border with two additional isolated sites close to Bordeaux and Marmande. All mosquitoes were heterozygous for this mutation and should not be phenotypically resistant to pyrethroid insecticide. Four other mutations were identified in our targeted genomic sequence: I1532T, M1006L, M1586L, M995L. Sequencing a section of maternally inherited mitochondrial genome confirmed that the spread of Ae. albopictus in France originated from founders with haplogroup A1. These findings contribute to the broader understanding of resistance dynamics in Europe and can inform targeted approaches to mitigate the impact of resistance on vector control.

genetics↗